Cholinergic neurons with monoamine oxidase type B (MAOB)-activity in the laterodorsal tegmental nucleus of the mouse

No neurons in the laterodorsal tegmental nucleus (LDTg) show monoamine oxid ase (MAO) activity in the rat or monkey. However, in our recent study, many LDTg neurons with MAO type B (MAOB)-activity were found in MAOA-deficient mice that were derived from C3H mouse line. In the present study, LDTg neur ons with MAOB-activity were found not only in normal C3H mouse but also in BALB/C and C57BL/6 mouse lines: MAO histochemistry revealed LDTg neurons wi th MAO-activity even after pharmacological suppression of MAOA-activity wit h clorgyline, a specific MAOA inhibitor, but not after pharmacological supp ression of MAOB-activity with eprenyl, a specific MAOB inhibitor. LDTg neur ons with MAOB-activity also showed NADPH-diaphorase-activity, a marker of c holinergic neurons. (C) 1999 Elsevier Science Ireland Ltd. All rights reser ved.